use warnings;
use List::Util qw( min max );
-our $VERSION = '1.02';
+our $VERSION = '1.05';
# ITU-R recommendation 601 luma co-efficients
our $kr = .299;
}
sub newyuv {
- # convert from YPbPr values 0..255 (or hex string)
+ # convert from YPbPr values -1..1
my $class = shift;
- my ($y, $cb, $cr) = @_ >= 3 ? @_ : (map {hex} $_[0] =~ /(..)/g);
-
- $_ -= 128 for $cb, $cr;
- $_ /= 255 for $y, $cb, $cr;
+ my ($y, $cb, $cr) = @_;
my @rgb = map { max(0, min(255, $_ * 255)) } (
$y + $cr,
bless \@rgb, $class;
}
+sub newyuv8 {
+ # convert from YPbPr values 0..255 (or hex string)
+ my $class = shift;
+ my ($y, $cb, $cr) = @_ >= 3 ? @_ : (map {hex} $_[0] =~ /(..)/g);
+
+ $_ -= 128 for $cb, $cr;
+ $_ /= 255 for $y, $cb, $cr;
+
+ $class->newyuv($y, $cb, $cr);
+}
+
sub luminance {
# perceived brightness
my ($r, $g, $b) = @{ $_[0] };
}
sub hue {
+ # colour shift (red = 0 .. 1)
my ($r, $g, $b) = @{ $_[0] };
my $hue = atan2 sqrt(3) * ($g - $b), $r*2 - $g - $b;
- return ($hue + $PI) / $PI / 2; # 0 .. 1
+ $hue /= $PI * 2; # -.5 .. .5
+ $hue++ if $hue < 0; # fp $hue %= 1
+ return $hue;
+}
+
+sub hsv {
+ my ($rgb) = @_;
+ my $v = max(@{$rgb});
+ return $rgb->hue, abs(min(@{$rgb}) - $v), $v;
}
sub rgb24 {